1) Field of the Invention
The present invention relates to bioactive egg protein hydrolysates, methods of making active protein hydrolysates and functional foods and food supplements comprising these in suitable amounts. Functional foods, food supplements and the active protein hydrolysates as functional ingredients as such are particularly suited for lowering blood pressure and may be consumed both prophylactically and therapeutically. In addition, the hydrolysates, and compositions comprising these, may be used to treat or prevent one or more components of metabolic disorders and cardiovascular disease risk factors, such as the metabolic syndrome.
2) Description of Related Art
Worldwide cardiovascular diseases have tremendous effects on overall health status and economic involvement of its inhabitants and on economy in general. Every year, 1.5 million people die from cardiovascular disease (CVD) in the Member States of the European Union (European Heart Network). Furthermore, nearly 1.4 million years of life lost in disability are due to CVD of which more than half (over 0.7 million) are lost due to stroke. There is a strong association between the level of blood pressure and the risk of stroke and coronary heart disease and a high percentage of the EU inhabitants suffers from (mildly) elevated blood pressure, the particular group of elderly being even at higher risks.
Hypertension usually coexists within a cluster of risk factors. Angiotensin-I Converting Enzyme (ACE) inhibitors not only lower blood pressure but also positively influence many other aspects of the atherogenic milieu. Evidence for the benefits of ACE inhibitors in reducing cardiovascular morbidity and mortality in patients with myocardial infarction and congestive heart failure is well established by now. Even a mild reduction of blood pressure can positively influence mortality and morbidity rates. Recent analysis of the nature of CVD risk suggests that diet should be receiving greater attention than it has done in the past, as a fundamental, underlying risk factor (European Heart Network, Position Paper, 1998). In this Position Paper it was concluded that this fact implies that provision of a healthy diet needs to be moved to the centre stage of CVD prevention activities.
ACE generates Angiotensin-II having vasopressor activity, including vasoconstriction, by cleaving C-terminal His-Leu off the otherwise inactive Angiotensin-I. It is known that hypertension can be treated by inhibiting the function of ACE. A number of chemical drugs with in vivo ACE inhibitory activity exist, such as Moexipril, Quinapril, Enalapril, Lisinopril, Perindopril, Ramipril, Trandolapril, and Benazepril. Such drugs often have side effects and there is a danger of taking overdoses. In addition they are generally not suitable for prophylactic consumption. There is, therefore, a need for alternative, natural ACE inhibitors, which are not harmful when ingested (prophylactically) by subjects not suffering from raised blood pressure, but which actively lower blood pressure in subjects with (mildly) raised blood pressure. Preferably, such products are ingested either as food supplements (e.g. in the form of tablets, sachets, etc.) or as functional food (e.g. in the form of drinks, semi-solid or solid food products). Regular consumption of such food supplements or functional food products is expected to result in a decrease of costs in the health care sector representing 2% of the cost involved in CVD and a decrease of people suffering from CVD in the EU by 5%. Also, the average disease-free years can likely be extended by at least 3 years. In addition production processes of these products is more environmentally friendly and production costs are much lower compared to chemical drugs.
A number of antihypertensive compositions derived from natural sources have already been described. EP 1 228 708 describes the use of a milk-derived protein and peptide fraction with high blood pressure reducing activity. EP0583074 describes the also milk-derived Val-Pro-Pro comprising peptides with ACE inhibitory activity and fermented food products therewith. WO01/32905 describes the fermentation of casein-containing starting material with lactic acid bacteria for the preparation of antihypertensive peptides. U.S. Pat. No. 6,514,941 relates to casein hydrolysate enriched in hypertensive peptides. WO01/85984 describes the use of whey protein hydrolysates with ACE inhibitory activity and antihypertension activity. EP1094071 relates to a peptide obtained from fish meat for use as an antihypertensive agent.